How
then, do these four sublime states pervade and suffuse each other?

Unbounded love guards
compassion against turning into partiality, prevents it from making
discriminations by selecting and excluding and thus protects it from
falling into partiality or aversion against the excluded side.

Love
imparts to equanimity its selflessness, its boundless nature and even its fervour.
For fervour, too, transformed and controlled, is part of perfect equanimity, strengthening
its power of keen penetration and wise restraint.

Compassion
prevents love and sympathetic joy from forgetting that, while both are enjoying
or giving temporary and limited happiness, there still exist at that time most
dreadful states of suffering in the world. It reminds them that their happiness
coexists with measureless misery, perhaps at the next doorstep. It is a reminder
to love and sympathetic joy that there is more suffering in the world than they
are able to mitigate; that, after the effect of such mitigation has vanished,
sorrow and pain are sure to arise anew until suffering is uprooted entirely at
the attainment of Nibbana. Compassion does not allow that love and sympathetic
joy to shut themselves up against the wide world by confining themselves to a
narrow sector of it. Compassion prevents love and sympathetic joy from turning
into states of self-satisfied complacency within a jealously guarded petty happiness.
Compassion stirs and urges love to widen its sphere; it stirs and urges sympathetic
joy to search for fresh nourishment. Thus it helps both of them to grow into truly
boundless states (appamanna).

Compassion guards
equanimity from falling into a cold indifference, and keeps it from
indolent or selfish isolation. Until equanimity has reached perfection,
compassion urges it to enter again and again the battlefield of the
world, in order to be able to stand the test, by hardening and strengthening
itself.

Sympathetic joy
holds compassion back from becoming overwhelmed by the sight of the
world's suffering, from being absorbed by it to the exclusion of everything
else. Sympathetic joy relieves the tension of mind, soothes the painful
burning of the compassionate heart. It keeps compassion away from melancholic
brooding without purpose, from a futile sentimentality that merely weakens
and consumes the strength of mind and heart. Sympathetic joy develops
compassion into active sympathy.

Sympathetic
joy gives equanimity the mild serenity that softens its stern appearance. It is
the divine smile on the face of the Enlightened One, a smile that persists in
spite of his deep knowledge of the world's suffering, a smile that gives solace
and hope, fearlessness and confidence: "Wide open are the doors to deliverance",
thus it speaks.

Equanimity rooted
in insight is the guiding and restraining power for the other three
sublime states. It points out to them the direction they have to take,
and sees to it that this direction is followed. Equanimity guards love
and compassion from being dissipated in vain quests and from going astray
in the labyrinths of uncontrolled emotion. Equanimity, being a vigilant
self-control for the sake of the final goal, does not allow sympathetic
joy to rest content with humble results, forgetting the real aims we
have to strive for.

Equanimity,
which means "even-mindedness", gives to love an even, unchanging firmness
and loyalty. It endows it with the great virtue of patience. Equanimity furnishes
compassion with an even, unwavering courage and fearlessness, enabling it to face
the awesome abyss of misery and despair which confront boundless compassion again
and again. To the active side of compassion, equanimity is the calm and firm hand
led by wisdom - indispensable to those who want to practice the difficult art
of helping others. And here again equanimity means patience, the patient devotion
to the work of compassion.

In these and other
ways equanimity may be said to be the crown and culmination of the other
three sublime states. The first three, if unconnected with equanimity
and insight, may dwindle away due to the lack of a stabilizing factor.
Isolated virtues, if unsupported by other qualities which give them
either the needed firmness or pliancy, often deteriorate into their
own characteristic defects. For instance, loving-kindness, without energy
and insight, may easily decline to a mere sentimental goodness of weak
and unreliable nature. Moreover, such isolated virtues may often carry
us in a direction contrary to our original aims and contrary to the
welfare of others, too. It is the firm and balanced character of a person
that knits isolated virtues into an organic and harmonious whole, within
which the single qualities exhibit their best manifestations and avoid
the pitfalls of their respective weaknesses. And this is the very function
of equanimity, the way it contributes to an ideal relationship between
all four sublime states.

Equanimity
is a perfect, unshakable balance of mind, rooted in insight. But in its perfection
and unshakable nature equanimity is not dull, heartless and frigid. Its perfection
is not due to an emotional "emptiness", but to a "fullness"
of understanding, to its being complete in itself. Its unshakable nature is not
the immovability of a dead, cold stone, but the manifestation of the highest strength.

In
what way, now, is equanimity perfect and unshakable? Whatever causes stagnation
is here destroyed, what dams up is removed, what obstructs is destroyed. Vanished
are the whirls of emotion and the meanderings of intellect. Unhindered goes the
calm and majestic stream of consciousness, pure and radiant. Watchful mindfulness
(sati) has harmonized the warmth of faith (saddha) with the penetrative
keenness of wisdom (panna); it has balanced strength of will (viriya)
with calmness of mind (samadhi); and these five inner faculties (indriya)
have grown into inner forces (bala) that cannot be lost again. They cannot
be lost because they do not lose themselves any more in the labyrinths of the
world (samsara), in the endless diffuseness of life (papanca). These
inner forces emanate from the mind and act upon the world, but being guarded by
mindfulness, they nowhere bind themselves, and they return unchanged. Love, compassion
and sympathetic joy continue to emanate from the mind and act upon the world,
but being guarded by equanimity, they cling nowhere, and return unweakened and
unsullied.

Thus
within the Arahat, the Liberated One, nothing is lessened by giving, and he does
not become poorer by bestowing upon others the riches of his heart and mind. The
Arahat is like the clear, well-cut crystal which, being without stains, fully
absorbs all the rays of light and sends them out again, intensified by its concentrative
power. The rays cannot stain the crystal with their various colours. They cannot
pierce its hardness, nor disturb its harmonious structure. In its genuine purity
and strength, the crystal remains unchanged. "Just as all the streams of
the world enter the great ocean, and all the waters of the sky rain into it, but
no increase or decrease of the great ocean is to be seen" - even so is the
nature of holy equanimity.

Holy equanimity,
or - as we may likewise express it - the Arahat endowed with holy equanimity,
is the inner centre of the world. But this inner centre should be well
distinguished from the numberless apparent centres of limited spheres;
that is, their so called "personalities", governing laws,
and so on. All of these are only apparent centres, because they cease
to be centres whenever their spheres, obeying the laws of impermanence,
undergo a total change of their structure; and consequently the centre
of their gravity, material or mental, will shift. But the inner centre
of the Arahat's equanimity is unshakable, because it is immutable. It
is immutable because it clings to nothing.

Says the Master:
"For one who clings, motion exists; but for one who clings not,
there is no motion. Where no motion is, there is stillness. Where stillness
is, there is no craving. Where no craving is, there is neither coming
nor going. Where no coming nor going is, there is neither arising nor
passing away. Where neither arising nor passing away is, there is neither
this world nor a world beyond, nor a state between. This, verily, is
the end of suffering." ~ UDANA 8:4